The present disclosure relates to a cleaning unit, an image forming apparatus including the same and a shutter provided in the cleaning unit, which are preferably applied as a copying machine, a printer or the like.
There is an image forming apparatus provided with a cleaning unit eliminating a waste toner from an image forming face of an image carrier after an image is formed.
For example, a drum unit including a cleaning unit is provided with a rubbing roller and a cleaning blade scraping a waste toner from an image forming face of a photosensitive drum, a screw conveying the waste toner dropped in a casing, and a cup-like formed shutter opening/closing the casing. The waste toner is ejected from an ejecting port formed in the shutter to a toner conveying part and collected in a collecting case. When the drum unit (the cleaning unit) is detached from an apparatus main body, the shutter is turned around the axis to close the ejecting port.
Incidentally, in the above-mentioned cleaning unit, in a connecting portion of the ejecting port of the shutter and the toner conveying part, a seal is provided to prevent a leak of the waste toner. The seal is arranged in close contact with a circumference edge of the ejecting port or an outer end face (an outside face) of the shutter to prevent the leak of the waste toner.
However, when the cleaning unit is attached/detached in a direction orthogonal to an action direction of the close contact force of the outer end face of the shutter to the seal, this close contact force causes resistance to attaching/detaching work. This makes the attaching/detaching work difficult. In addition, a close contact condition of the outer end face of the shutter to the seal causes a friction force to prevent the turn of the shutter. Therefore, there is a problem that the ejecting port is inappropriately closed. This problem may be solved by weakening the close contact force between the shutter and seal. However, in order to prevent the leak of the waste toner, it is impossible to lightly weaken the close contact force.
In a case where the shutter is smoothly turned, since the close of the ejecting port advances by interlocking with the advance of the turn of the shutter, the close contact condition to the seal is released before the ejecting port is completely closed by the shutter. Therefore, there is a problem that the waste toner is leaked from the ejecting port when the cleaning unit is detached from the apparatus main body.